The Labour Party insisted one of its senior ministers had a direct input into Minister for Justice Alan Shatter’s latest response to the Garda Síochána Ombudsman Commission bugging controvery.

Amid growing controvery over Mr Shatter’s handling of the affair, he announced a review, headed by a retired High Coutt judge, into the matter.

Sources said the junior Coalition partner wanted Minister for Communications Pat Rabbitte directly involved in drafting a Government amendment to a Sinn Fein motion on the issue in the Dail last night.

Amid increasing tension between the coalition parties, a Fine Gael source said however that “Everyone contributes on a counter motion.”

The independent investigation into the alleged bugging is to report back to the Oireachtas within two months.

The terms of reference for the investigation, which the Government described as a review, are to be announced later today. It is understood Mr Justice John Cooke, who recently chaired the constituency review of Dáil and European Parliament constituencies, will head up the inquiry.

It will be an informal review and will not be established as a commission for investigation. It is not yet clear if the judge will merely be reviewing documents or if he will be able to call witnesses and carry out interviews.

The Cabinet also decided to refer legislation governing GSOC to the Oireachtas Justice and Defence Committee, which will assess whether it needs to be strengthened.

Taoiseach Enda Kenny, Tánaiste Eamon Gilmore and Mr Shatter have all ruled out an independent investigation in recent days.

While the Government spokesman insisted new information given to Mr Shatter partly prompted the change of course, Labour sources said its ministers became increasingly concerned about the “drip drip” of information emerging on the issue and Mr Shatter’s handling of it.

Sinn Féin had already tabled a private member’s motion in the Dáil calling for an independent inquiry but Labour insisted its input was in the response, or the wording of an amendment to the motion, and the “direction of travel” of the Coalition reaction.

The Labour ministers formed the view at their weekly pre-Cabinet meeting.

“Labour ministers also agreed that Pat Rabbitte and Alan Shatter would draft the Government response to the Sinn Fein private member’s motion,” a source said.

However, a senior Government source insisted Mr Shatter “released his statement, and nobody else”, while Fine Gael sources questioned how strongly Labour had expressed disquiet up to now.

A Government spokesman said Mr Shatter himself acknowledged the need for an inquiry. “Minister Shatter was of the view that less clarity was emerging, not more,” he said, while also adding there is still “no definitive evidence” that the GSOC’s headquarters were bugged.

Speaking last night in the Dáil, Mr Shatter said there is no one more committed than him in maintaining the independence of the GSOC.

He said he had come under “continued political attack” suggesting he undermined the GSOC. However, he said the ongoing controversy and new information received by him warranted “clarity”.

Mr Shatter told the Dáil a “peer review” he commissioned on what happened at GSOC had established that a wi-fi device in GSOC’s offices connecting to an external wi-fi in an action regarded by the UK company Verrimus as suspect, was in fact connecting with the wi-fi in a coffee shop trading in the same building as GSOC and was not a security breach.

However, Mr Shatter made no mention of the conclusions of the review carried out on his behalf in relation to the other two anomalies flagged by Verrimus.

These included the mysterious presence of a UK 3G mobile phone network in tests conducted from GSOC’s offices despite such networks not operating in the Republic.

Verrimus also carried out tests on the office landline of GSOC chairman Simon O’Brien, which concluded it was bugged.